scholarly journals In VitroActivity of Ceftazidime-NXL104 against 396 Strains of β-Lactamase-Producing Anaerobes

2011 ◽  
Vol 55 (7) ◽  
pp. 3616-3620 ◽  
Author(s):  
Diane M. Citron ◽  
Kerin L. Tyrrell ◽  
Vreni Merriam ◽  
Ellie J. C. Goldstein

ABSTRACTNXL104, a novel β-lactamase inhibitor, was tested at a constant concentration of 4 μg/ml in combination with ceftazidime (CAZ), with and without added metronidazole, against 396 β-lactamase-producing strains of anaerobic bacteria. MIC50/MIC90values forBacteroides fragilisand theB. fragilisgroup were 8/16 and 64/>128 μg/ml, respectively. Although CAZ-NXL104 had limited activity against most anaerobic strains, in combination with metronidazole it shows potential for treating mixed infections involving resistantEnterobacteriaceaeand anaerobes.

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
C. Vreni Merriam ◽  
Diane M. Citron

ABSTRACT Tedizolid’s anaerobic activity is unappreciated. In this study, it was active against all 332 anaerobic isolates tested at ≤2 μg/ml except Bilophila wadsworthia and was more active than linezolid against Bacteroides fragilis group species (MIC90, 1 μg/ml versus 2 to 4 μg/ml). Tedizolid was active against Gram-positive anaerobes (MIC90 for clostridia, 0.25 to 1 μg/ml; MIC90 for anaerobic cocci, ≤0.06 to 0.25 μg/ml). Our data coupled with clinical reports indicate that clinicians should consider its use in mixed infections where Staphylococcus aureus and anaerobes are involved.


2013 ◽  
Vol 57 (6) ◽  
pp. 2620-2630 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
Kerin L. Tyrrell ◽  
C. Vreni Merriam

ABSTRACTBiapenem is a carbapenem being developed in combination with RPX7009, a new inhibitor of serine β-lactamases. Biapenem was tested alone and in combination with fixed concentrations of RPX7009 by agar dilution against 377 recent isolates of anaerobes. A separate panel of 27 isolates ofBacteroidesspp. with decreased susceptibility or resistance to imipenem was also tested. Comparator drugs included meropenem, piperacillin-tazobactam, ampicillin-sulbactam, cefoxitin, ceftazidime, metronidazole, clindamycin, and tigecycline plus imipenem, doripenem, and ertapenem for the 27 selected strains. For recent consecutive strains ofBacteroidesspecies, the MIC90for biapenem-RPX7009 was 1 μg/ml, with a MIC90of 4 μg/ml for meropenem. OtherBacteroides fragilisgroup species showed a MIC90of 0.5 μg/ml for both agents. The MIC90s for biapenem-RPX7009 were 0.25 μg/ml forPrevotellaspp., 0.125 μg/ml forFusobacterium nucleatumandFusobacterium necrophorum, 2 μg/ml forFusobacterium mortiferum, 0.5 μg/ml forFusobacterium varium, ≤0.5 μg/ml for Gram-positive cocci and rods, and 0.03 to 8 μg/ml for clostridia. Against 5B. fragilisstrains harboring a known metallo-beta-lactamase, biapenem-RPX7009 MICs were comparable to those of other carbapenems (≥32 μg/ml). AgainstBacteroidesstrains with an imipenem MIC of 2 μg/ml, biapenem-RPX7009 had MICs of 0.5 to 2 μg/ml, with MICs of 0.5 to 32 μg/ml for meropenem, doripenem, and ertapenem. For strains with an imipenem MIC of 4 μg/ml, the MICs for biapenem-RPX7009 were 4 to 16 μg/ml, with MICs of 8 to >32 μg/ml for meropenem, doripenem, and ertapenem. The inhibitor RPX7009 had no antimicrobial activity when tested alone, and it showed little or no potentiation of biapenem versus anaerobes. Biapenem-RPX7009 showed activity comparable to that of imipenem and was superior to meropenem, doripenem, and ertapenem against imipenem-nonsusceptibleBacteroidesspp.


2015 ◽  
Vol 59 (8) ◽  
pp. 4504-4509 ◽  
Author(s):  
Mamun-Ur Rashid ◽  
Staffan Rosenborg ◽  
Georgios Panagiotidis ◽  
Karin Söderberg-Löfdal ◽  
Andrej Weintraub ◽  
...  

ABSTRACTCeftaroline-avibactam is a new combination of the antibiotic ceftaroline with a novel non-β-lactam β-lactamase inhibitor, avibactam. The purpose of the present study was to investigate the effect of ceftaroline-avibactam on the human intestinal microbiota. Fourteen healthy volunteers received ceftaroline-avibactam (600 mg ceftaroline fosamil and 600 mg avibactam) intravenously over 2 h every 8 h on days 1 to 6 and as a single dose on day 7. Fecal samples were collected on day −1 (within 24 h of the first infusion on day 1) and on days 2, 5, 7, 9, 14, and 21.Escherichia colinumbers decreased during the study and normalized on day 21. An increased number ofKlebsiellabacteria appeared on day 14 and normalized on day 21. The number of other enterobacteria decreased during the study, and the number of enterococci decreased from days 2 to 7 and normalized on day 9.Candidanumbers increased from days 5 to 9 and normalized after day 14. The number of lactobacilli decreased during the study and recovered on day 14. The number of bifidobacteria decreased on day 2 and normalized on day 21. The number ofBacteroidesbacteria was unchanged.Clostridium difficilenumbers decreased on days 7 and 9 and increased on days 14 and 21. A toxigenicC. difficilestrain was detected in one volunteer on day 21 with no reported adverse events. Plasma samples were collected on days −1, 2, 5, and 7. Ceftaroline and avibactam concentrations were 0 to 34.5 mg/liter and 0 to 61.6 mg/liter, respectively, in plasma and 0 to 35.4 mg/kg and 0 to 98.5 mg/kg, respectively, in feces. (This study is registered in the European Clinical Trials Database [https://eudract.ema.europa.eu/] under number EudraCT 2012 004921-25.)


1979 ◽  
Vol 25 (9) ◽  
pp. 987-990 ◽  
Author(s):  
James E. Ogg ◽  
Sun Y. Lee ◽  
Betty J. Ogg

A new type of tube (the Lee tube) has been developed for use in the cultivation and enumeration of obligate anaerobes. The Lee tube is a double-walled, screw-capped tube which allows the formation of a thin cylinder of agar medium between the two walls. Anaerobiosis is achieved through deoxygenation of the deep cylinder of agar during sterilization, a minimum of head space, and use of a reducing agent to absorb oxygen introduced during the inoculation procedure. For several species of Clostridium, Bacteroides fragilis, Fusobacterium necrophorum, Veillonella alcalescens, and Pectinatus cerevisiiphilus, colony counts of cultures in the Lee tubes were comparable with those obtained in pour plates incubated in a BBL GasPak system and in anaerobic roll tubes.


2016 ◽  
Vol 60 (10) ◽  
pp. 6326-6332 ◽  
Author(s):  
David C. Griffith ◽  
Jeffery S. Loutit ◽  
Elizabeth E. Morgan ◽  
Stephanie Durso ◽  
Michael N. Dudley

ABSTRACTVaborbactam (formerly RPX7009) is a member of a new class of β-lactamase inhibitor with pharmacokinetic properties similar to those of many β-lactams, including carbapenems. The pharmacokinetics and safety of vaborbactam were evaluated in 80 healthy adult subjects in a first-in-human randomized, placebo-controlled, double-blind, sequential single- and multiple-ascending-dose study. A total of 10 dose cohorts were enrolled in the study, with 6 subjects randomized to receive 250 to 2,000 mg of vaborbactam and 2 subjects randomized to receive placebo in each cohort. Maximum concentrations for vaborbactam were achieved at the end of the 3-h infusion. Vaborbactam exposure (Cmaxand area under the concentration-time curve [AUC]) increased in a dose-proportional manner following multiple doses. There was no evidence of accumulation with multiple doses, consistent with the terminal half-life of ∼2 h. Both the volume of distribution (Vss) and plasma clearance were independent of dose. For the 2,000-mg dose, the plasma clearance was 0.17 ± 0.03 liters/h, the AUC from 0 h to infinity (AUC0–∞) was 144.00 ± 13.90 mg · h/liter, and theVsswas 21.80 ± 2.26 mg · h/liter. Urinary recovery was 80% or greater over 48 h across all dose groups. No subjects discontinued the study due to adverse events (AEs), and no serious AEs (SAEs) were observed. All AEs were mild to moderate and similar among the vaborbactam- and placebo-treated subjects, with mild lethargy as the only unique AE reported with the high dose of vaborbactam. Overall, this study revealed the safety, tolerability, and pharmacokinetic profile of vaborbactam and formed the basis for advancement into patient studies in combination with meropenem, including treatment of patients with carbapenem-resistantEnterobacteriaceae(CRE) infections. (This study is registered at ClinicalTrials.gov under identifier NCT01751269.)


2011 ◽  
Vol 56 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
James A. Karlowsky ◽  
Andrew J. Walkty ◽  
Heather J. Adam ◽  
Melanie R. Baxter ◽  
Daryl J. Hoban ◽  
...  

ABSTRACTClinical isolates of theBacteroides fragilisgroup (n= 387) were collected from patients attending nine Canadian hospitals in 2010-2011 and tested for susceptibility to 10 antimicrobial agents using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method.B. fragilis(59.9%),Bacteroides ovatus(16.3%), andBacteroides thetaiotaomicron(12.7%) accounted for ∼90% of isolates collected. Overall rates of percent susceptibility were as follows: 99.7%, metronidazole; 99.5%, piperacillin-tazobactam; 99.2%, imipenem; 97.7%, ertapenem; 92.0%, doripenem; 87.3%, amoxicillin-clavulanate; 80.9%, tigecycline; 65.9%, cefoxitin; 55.6%, moxifloxacin; and 52.2%, clindamycin. Percent susceptibility to cefoxitin, clindamycin, and moxifloxacin was lowest forB. thetaiotaomicron(n= 49, 24.5%),Parabacteroides distasonis/P. merdae(n= 11, 9.1%), andB. ovatus(n= 63, 31.8%), respectively. One isolate (B. thetaiotaomicron) was resistant to metronidazole, and two isolates (bothB. fragilis) were resistant to both piperacillin-tazobactam and imipenem. Since the last published surveillance study describing Canadian isolates ofB. fragilisgroup almost 20 years ago (A.-M. Bourgault et al., Antimicrob. Agents Chemother. 36:343–347, 1992), rates of resistance have increased for amoxicillin-clavulanate, from 0.8% (1992) to 6.2% (2010-2011), and for clindamycin, from 9% (1992) to 34.1% (2010-2011).


2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Alka Hasani ◽  
Saba Ebrahimzadeh ◽  
Fatemeh Hemmati ◽  
Aytak Khabbaz ◽  
Akbar Hasani ◽  
...  

Alteration in the composition of the gut microbiota can lead to a number of chronic clinical diseases. Akkermansia muciniphila is an anaerobic bacteria constituting 3–5% of the gut microbial community in healthy adults. This bacterium is responsible for degenerating mucin in the gut; its scarcity leads to diverse clinical disorders. In this review, we focus on the role of A. muciniphila in diabetes, obesity and atherosclerosis, as well as the use of this bacterium as a next-generation probiotic. In regard to obesity and diabetes, human and animal trials have shown that A. muciniphila controls the essential regulatory system of glucose and energy metabolism. However, the underlying mechanisms by which A. muciniphila alleviates the complications of obesity, diabetes and atherosclerosis are unclear. At the same time, its abundance suggests improved metabolic disorders, such as metabolic endotoxemia, adiposity insulin resistance and glucose tolerance. The role of A. muciniphila is implicated in declining aortic lesions and atherosclerosis. Well-characterized virulence factors, antigens and cell wall extracts of A. muciniphila may act as effector molecules in these diseases. These molecules may provide novel mechanisms and strategies by which this bacterium could be used as a probiotic for the treatment of obesity, diabetes and atherosclerosis.


2021 ◽  
Vol 70 (7) ◽  
Author(s):  
Rosemonde Isabella Power ◽  
Nichola Elisa Davies Calvani ◽  
Yaarit Nachum-Biala ◽  
Harold Salant ◽  
Shimon Harrus ◽  
...  

Introduction. Bartonellosis is an emerging zoonotic disease caused by bacteria of the genus Bartonella . Mixed Bartonella infections are a well-documented phenomenon in mammals and their ectoparasites. The accurate identification of Bartonella species in single and mixed infections is valuable, as different Bartonella species have varying impacts on infected hosts. Gap Statement. Current diagnostic methods are inadequate at identifying the Bartonella species present in mixed infections. Aim. The aim of this study was to adopt a Next Generation Sequencing (NGS) approach using Illumina sequencing technology to identify Bartonella species and demonstrate that this approach can resolve mixed Bartonella infections. Methodology. We used Illumina PCR amplicon NGS to target the ssrA and gltA genes of Bartonella in fleas collected from cats, dogs and a hedgehog in Israel. We included artificially mixed Bartonella samples to demonstrate the ability for NGS to resolve mixed infections and we compared NGS to traditional Sanger sequencing. Results. In total, we identified 74 Ctenocephalides felis, two Ctenocephalides canis, two Pulex irritans and three Archaeopsylla e. erinacei fleas. Real-time PCR of a subset of 48 fleas revealed that twelve were positive for Bartonella , all of which were cat fleas. Sanger sequencing of the ssrA and gltA genes confirmed the presence of Bartonella henselae , Bartonella clarridgeiae and Bartonella koehlerae . Illumina NGS of ssrA and gltA amplicons further confirmed the Bartonella species identity in all 12 flea samples and unambiguously resolved the artificially mixed Bartonella samples. Conclusion. The adaptation and multiplexing of existing PCR assays for diversity profiling via NGS is a feasible approach that is superior to traditional Sanger sequencing for Bartonella speciation and resolving mixed Bartonella infections. The adaptation of other PCR primers for Illumina NGS will be useful in future studies where mixed bacterial infections may be present.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Anna Kędzia ◽  
Andrzej W. Kędzia

Introduction. Abies whitebark (Abies sibirica L.) belonging to the family Pinaceae. The tree grown in Mongol, China and Siberian taiga. Produced the pichtae oil, which is obtained by hydrodistillation method. It contain: α-pinene, β-pinene, β-caryophyllene, bornyl acetate, camphene, mircene and cineole. The oil exhibiting expectorant, analgesic, anti-inflammatory, antialergic, liver restorative, adaptogenic and antioxidant properties. It has antimicrobial activity. Aim. The aim of the date was to determine the susceptibility of anaerobic bacteria isolated from patients to pichtae oil. Material and methods. The investigated 49 strains of bacteria isolated from patients from genus Bacteroides (7 strains), Parabacteroides (1), Prevotella (8), Porphyromonas (5), Tannerella (1), Fusobacterium (6), Finegoldia (4), Parvimonas (2), Peptostreptococcus (4), Actinomyces (4), Bifidobacterium (1), Propionibacterium (6), and 10 reference strains. The concentrations the oil were the following: 2.5, 5.0, 7.5, 10.0, 15.0 and 20.0 mg/ml. The pichtae oil was added to Brucella agar with 5% defibrynated sheep blood, menadione and hemin. Inoculum containing 106 CFU/ml was seeded with Steers replicator upon the agar with oil or without oil (strains growth control). The incubation was carried out in anaerobic jars containing 10% C02 , 10% H2 and 80% N2 , palladic catalyst and anaerobic indicator, at 37°C for 48 hrs. The MIC was defined as the lowest concentration of the pichtae oil that completely inhibited growth the anaerobic bacteria. Results. The results investigation indicated that from Gram-negative rods Tannerella forsythia (MIC = 5.0 mg/ml), Bacteroides fragilis and Bacteroides uniformis (MIC = 7.5 mg/ml) were the most susceptible to pichtae oil. The growth of Prevotella strains were inhibited by concentrations in ranges 5.0-15.0 mg/ml. The Prevotella bivia (MIC 10.0-15.0 mg/ml) and Prevotella buccalis (MIC = 15.0 mg/ml) were the most resistant. The tested oil was active on account genus of Fusobacterium strains in concentrations 5.0-10.0 mg/ml. The Gram-positive cocci were the more sensitive then rods. The growth was inhibited by concentrations in ranges ≤ 2.5-10.0 mg/ml. The oil was equally effective against Gram-positive rods (MIC ≤ 2.5-10.0 mg/ml). From this bacteria the more susceptible were the strains of Actinomyces (MIC ≤ 2.5-7.5 mg/ml) and the least a rods from genus of Bifidobacterium (MIC = 10.0 mg/ml). The date indicated, that the Gram-positive anaerobes were the more susceptible to pichtae oil than Gram-negative rods. Conclusions. From among the Gram-negative bacteria the more susceptible to pichtae oil were the rods from genus Tannerella forsythia, Bacteroides fragilis and Bacteroides uniformis. Gram-positive anaerobic cocci were the more susceptible then Gram-positive rods. The pichtae oil was the more active towards Gram-positive bacteria then Gram-negative anaerobic rods.


1996 ◽  
Vol 40 (9) ◽  
pp. 2232-2235 ◽  
Author(s):  
H M Wexler ◽  
E Molitoris ◽  
D Molitoris ◽  
S M Finegold

The antimicrobial activity of trovafloxacin for 557 strains of anaerobic bacteria was determined by the National Committee for Clinical Laboratory Standards-approved Wadsworth agar dilution technique. The species tested included Bacteroides fragilis (n = 91), other members of the B. fragilis group (n = 130), Campylobacter gracilis (n = 15), other Bacteroides spp. (n = 16), Prevotella spp. (n = 49), Porphyromonas spp. (n = 15), Fusobacterium spp. (n = 62), Bilophila wadsworthia (n = 24), Sutterella wadsworthensis (n = 21), Clostridium spp. (n = 61), Peptostreptococcus spp. (n = 38), and gram-positive non-spore-forming rods (n = 35). Trovafloxacin inhibited all strains of B. fragilis at < or = 0.5 microgram/ml, 99% of other B. fragilis group species at < or = 2 micrograms/ml, and 96% of all anaerobes tested at < or = 2 micrograms/ml.


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